when i measure my brass backwards on a sinclair my case heads are about .007 out of round. Is this bad for accuracy? Can it be fixed?. Could my bolt be the the cause?

If you are shooting a high end benchrest rifle yes this could be an accuracy problem.
If you are shooting any other type of rifle,it's not likely to be a notable problem accuracy wise.

muck

Chambers are a bit oversize to allow the cartridge to chamber easily. The thinner side of the case wall will expand quicker then the rest when the cartridge is fired and shows more expansion at this point on your brass. It is nothing to get excited about unless as noted you have a bench rifle with supposedly a much tighter then factory chamber.